Power-tool cutting device

Abstract

A power-tool cutting device that is free of a torque-transmitting element includes at least one cutting strand and at least one guiding unit for guiding the cutting strand. The guiding unit together with the cutting strand forms a closed system. The power-tool cutting device has at least one preloading unit that is arranged on the guiding unit. The preloading unit is configured for automatic play compensation and/or tolerance compensation of the cutting strand at least during a state of the guiding unit in which the guiding unit is removed from a coupling device of a portable power tool.

Claims

1. A power tool system, comprising: at least one power-tool parting device configured without a torque transmission element, the power-tool parting device including: at least one cutting strand, at least one guide unit onto which the cutting strand is guided, the guide unit together with the cutting strand constitutes a closed system, and at least one pretensioning unit disposed on the guide unit, the pretensioning unit configured to automatically compensate for one or more of play and tolerance of the cutting strand at least when the guide unit is in a state in which the guide unit is demounted from a coupling device of a portable power tool; and at least one portable power tool that includes at least one coupling device configured to couple to the power-tool parting device in one or more of a form-fitting manner and a force-fitting manner, wherein the pretensioning unit has at least one cutting-strand holding element that has at least one insertion functional face configured to effect at least one force component contrary to a pretensioning force of a pretensioning element of the pretensioning unit at least while the power-tool parting device is disposed on the coupling device.

2. A power-tool parting device configured without a torque transmission element, comprising: at least one cutting strand; at least one guide unit onto which the cutting strand is guided, the guide unit together with the cutting strand constitutes a closed system; and at least one pretensioning unit disposed on the guide unit, the pretensioning unit configured to automatically compensate for one or more of play and tolerance of the cutting strand at least when the guide unit is in a state in which the guide unit is demounted from a coupling device of a portable power tool, wherein the pretensioning unit has at least one resilient pretensioning element having a first end and a second end, the pretensioning element is supported at the first end on at least one cutting-strand holding element of the pretensioning unit and is supported at the second end on at least one coupling element of the guide unit.

3. The power-tool parting device as claimed in claim 2, wherein the at least one cutting-strand holding element is movably mounted.

4. The power-tool parting device as claimed in claim 2, wherein the pretensioning unit is disposed on the guide unit at least substantially in mirror symmetry in relation to a cutting plane of the cutting strand.

5. The power-tool parting device as claimed in claim 2, wherein the at least one cutting-strand holding element delimits at least one holding recess of the pretensioning unit that has a maximum width that is less than a maximum cutting-strand thickness of the cutting strand.

6. The power-tool parting device as claimed in claim 2, wherein the pretensioning unit has one or more of at least one force-fit element and at least one form-fit element that is configured to secure the at least one cutting-strand holding element of the pretensioning unit against movement in a cutting plane of the cutting strand.

7. A power-tool parting device configured without a torque transmission element, comprising: at least one cutting strand; at least one guide unit onto which the cutting strand is guided, the guide unit together with the cutting strand constitutes a closed system; and at least one pretensioning unit disposed on the guide unit, the pretensioning unit configured to automatically compensate for one or more of play and tolerance of the cutting strand at least when the guide unit is in a state in which the guide unit is demounted from a coupling device of a portable power tool, wherein the pretensioning unit comprises at least two cutting-strand holding elements, which together delimit a holding recess of the pretensioning unit, and wherein at least one distance element of the pretensioning unit is disposed on at least one of the cutting-strand holding elements in order to ensure a feed-through distance.

8. The power-tool parting device as claimed in claim 7, wherein the pretensioning unit has one or more of at least one force-fit element and at least one form-fit element that fixes the at least two cutting-strand holding elements of the pretensioning unit to each other in one or more of a form-fitting manner and a force-fitting manner, at least in a cutting plane of the cutting strand.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages are disclosed by the following description of the drawings. An exemplary embodiment of the disclosure is represented in the drawings. The drawings, the description and the claims contain numerous features in combination. Persons skilled in the art will also expediently consider the features individually and combine them to create appropriate further combinations.

(2) There are shown in:

(3) FIG. 1 a portable power tool according to the disclosure, having a power-tool parting device according to the disclosure, in a schematic representation,

(4) FIG. 2 a detail view of the power-tool parting device according to the disclosure, in a schematic representation,

(5) FIG. 3 a sectional view of the power-tool parting device according to the disclosure along the longitudinal axis of the power-tool parting device according to the disclosure from FIG. 2, in a schematic representation, and

(6) FIG. 4 a detail view of two cutting-strand holding elements of the power-tool parting device according to the disclosure, in a schematic representation.

DETAILED DESCRIPTION

(7) FIG. 1 shows a portable power tool 20, having a power-tool parting device 10, which together constitute a power-tool system. The portable power tool 20 has at least one coupling device 18 for coupling in a form-fitting and/or force-fitting manner to the power-tool parting device 10. The coupling device 18 in this case may be realized as a bayonet fixing, snap fixing and/or as another coupling device, considered appropriate by persons skilled in the art. The portable power tool 20 has at least one torque transmission element 56. The torque transmission element 56 in this case may be realized as a toothed wheel, in particular as a pinion. The power-tool parting device 10 comprises at least one cutting strand 12, and at least one guide unit 14 for guiding the cutting strand 12. The guide unit 14, together with the cutting strand 12, constitutes a closed system. The torque transmission element 56 engages directly in the cutting strand 12 for the purpose of driving the cutting strand 12.

(8) The portable power tool 20 additionally has a power tool housing 60, which encompasses a drive unit 62 and a transmission unit 64 of the portable power tool 20. The drive unit 62 and the transmission unit 64 are connected to each other, in a manner already known to persons skilled in the art, for the purpose of generating a driving torque that can be transmitted to the power-tool parting device 10. The transmission unit 64 is preferably realized as a bevel gear transmission. The drive unit 62 is preferably realized as an electric motor unit. It is also conceivable, however, for the drive unit 62 and/or the transmission unit 64 to be of a different design, considered appropriate by persons skilled in the art, such as, for example, the transmission unit 64 designed as a worm gear transmission, etc. The drive unit 62 is designed to drive the cutting strand 12 of the power-tool parting device 10, in at least one operating state, via the transmission unit 64. In the guide unit 14 of the power-tool parting device 10, the cutting strand 12 is moved in the guide unit 14, along a cutting direction 66 of the cutting strand 12, in particular relative to the guide unit 14.

(9) FIG. 2 shows the power-tool parting device 10 in a state of having been demounted from the coupling device 18 of the portable power tool 20. The power-tool parting device 10 is realized without a torque transmission element 56. The power-tool parting device 10 has the cutting strand 12 and the guide unit 14, which together constitute a closed system. The cutting strand 12 is guided by means of the guide unit 14. The guide unit 14 has at least one guide element realized as a guide groove (not represented in greater detail here), by means of which the cutting strand 12 is guided. The cutting strand 12 is guided by means of edge regions of the guide unit 14 that delimit the guide groove. It is also conceivable, however, for the guide element to be realized in a different manner, considered appropriate by persons skilled in the art, such as, for example, as a rib type formation on the guide unit 14 that engages in a recess on the cutting strand 12. The cutting strand 12 additionally comprises a multiplicity of cutter carrier elements 68, which are connected to each other and form the cutting strand 12 realized as a cutting chain.

(10) The power-tool parting device 10 additionally comprises at least one pretensioning unit 16, which is provided on the guide unit 14 and is designed to automatically compensate play and/or tolerance of the cutting strand 12, at least while the guide unit 14 is in a state of having been demounted from the coupling device 18 of the portable power tool 20. The pretensioning unit 16 is disposed, at least partly, on a drive side 70 of the guide unit 14. The pretensioning unit 16 is disposed on the guide unit 14, at least substantially in mirror symmetry in relation to the cutting plane 58 of the cutting strand 12. The guide unit 14 comprises at least one coupling element 32 disposed on the guide unit 14. The coupling element 32 is disposed on an outer face 72 of the guide unit 14. The guide unit 14 additionally comprises at least one further coupling element 34, disposed on the guide unit 14 (FIG. 3). The further coupling element 34 is disposed on a further outer face 74 of the guide unit 14, which is at least substantially parallel to the outer face 72. The coupling element 32 and the further coupling element 34 are disposed on the guide unit 14, substantially in mirror symmetry in relation to each other with respect to the cutting plane 58 of the cutting strand 12 (FIG. 3). It is likewise conceivable that, in an exemplary embodiment of the power-tool parting device 10 that is not represented in greater detail here, the guide unit 14, as an alternative to having the coupling element 32 and the further coupling element 34, has a single coupling element that is preferably disposed on the guide unit 14 in mirror symmetry in relation to the cutting plane 58 of the cutting strand 12 and that, in particular, has all features of the coupling element 32 and of the further coupling element 34. Particularly preferably, by means of the coupling element 32 and the further coupling element 34, the guide unit 14, in particular the power-tool parting device 10, is secured against twisting resulting from transmission of torques by the torque transmission element 56 of the portable power tool 20 while in a state of having been disposed on the coupling device 18 of the portable power tool 20.

(11) The pretensioning unit 16 additionally comprises at least one cutting-strand holding element 24 disposed on the guide unit 14. The cutting-strand holding element 24 is surrounded, at least partly, by the coupling element 32. The pretensioning unit 16 additionally comprises at least one further cutting-strand holding element 26, disposed on the guide unit 14 (FIG. 3). The further cutting-strand holding element 26 is surrounded, at least partly, by the further coupling element 34. Furthermore, the pretensioning unit 16 comprises at least one mounting opening 76, which is designed for easy mounting of a resilient pretensioning element 22 of the pretensioning unit 16 on the pretensioning unit 16. The pretensioning unit 16 additionally comprises at least one further mounting opening 78, which is designed for easy mounting of the resilient pretensioning element 22 on the pretensioning unit 16. Preferably, the mounting opening 76 is disposed on the coupling element 32. Preferably, the further mounting opening 78 is disposed on the further coupling element 34. The mounting opening 76 is delimited by at least one edge region of the coupling element 32. The further mounting opening 78 is delimited by at least one edge region of the further coupling element 34. The resilient pretensioning element 22 can be disposed on the coupling element 32 and on the further coupling element 34 through at least one of the mounting openings 76, 78. The resilient pretensioning element 22 can be disposed in a functional position on the pretensioning unit 16 by being inserted through at least one of the mounting openings 76, 78. In the functional position, the pretensioning element 22 bears at least partly against the edge region of the coupling element 32 that delimits the mounting opening 76, and against the edge region of the further coupling element 34 that delimits the further mounting opening 78. In the functional position, the pretensioning element 22 bears at least partly against the cutting-strand holding element 24 and against the further cutting-strand holding element 26. The cutting-strand holding element 24 and the further cutting-strand holding element 26 are disposed on the guide unit 14, substantially in mirror symmetry in relation to each other with respect to the cutting plane 58 of the cutting strand 12. It is likewise conceivable, in an exemplary embodiment of the power-tool parting device 10 that is not represented in greater detail here, for the pretensioning unit 16, as an alternative to having the cutting-strand holding element 24 and the further cutting-strand holding element 26, to have a single cutting-strand holding element that, preferably, is disposed on the guide unit 14 in mirror symmetry in relation to the cutting plane 58 of the cutting strand 12 and that, in particular, has all features of the cutting-strand holding element 24 and of the further cutting-strand holding element 26. The cutting-strand holding element 24 and the further cutting-strand holding element 26 are disposed in a movably mounted manner on the guide unit 14. The cutting-strand holding element 24 and the further cutting-strand holding element 26 are mounted so as to be translationally movable relative to the guide unit 14. The cutting-strand holding element 24 and the further cutting-strand holding element 26 are mounted so as to be translationally movable relative to the coupling element 32 and the further coupling element 34. The coupling element 32 has at least one guide groove 84, which is designed to guide the cutting-strand holding element 24 in a direction parallel to the longitudinal direction of the guide unit 14. The further coupling element 34 has at least one further guide groove 86, which is designed to guide the further cutting-strand holding element 26 in a direction parallel to the longitudinal direction of the guide unit 14. It is likewise conceivable for the coupling element 32 and/or the further coupling element 34, as an alternative to having the guide groove 84, 86, to have a guide extension, which is designed to guide the cutting-strand holding element 24 and/or the further cutting-strand holding element 26, in particular as a result of action in combination with a guide groove disposed on the cutting-strand holding element 24 and/or on the further cutting-strand holding element 26. It is additionally conceivable that, in an exemplary embodiment of the power-tool parting device 10 that is not represented in greater detail here, the pretensioning unit 16, as an alternative to having the cutting-strand holding element 24 and the further cutting-strand holding element 26, has a single cutting-strand holding element, which can be guided in the guide groove 84 and/or the further guide groove 86.

(12) Furthermore, the pretensioning unit 16 has at least one resilient pretensioning element 22, which is disposed on at least one of the movably mounted cutting-strand holding elements 24, 26 of the pretensioning unit 16 (FIG. 3). In the exemplary embodiment shown in FIGS. 2 to 4, the at least one resilient pretensioning element 22 of the pretensioning unit 16 is disposed on both movably mounted cutting-strand holding elements 24, 26 of the pretensioning unit 16. It is likewise conceivable that, in an exemplary embodiment of the power-tool parting device 10 that is not represented in greater detail here, the at least one resilient pretensioning element 22 of the pretensioning unit 16 is disposed on a single movably mounted cutting-strand holding element of the pretensioning unit 16. The two movably mounted cutting-strand holding elements 24, 26 hold the cutting strand 12 in a tensioned state when the guide unit 14 is in a state of having been demounted from the coupling device 18 of the portable power tool 20.

(13) The cutting-strand holding elements 24, 26 delimit a holding recess 36 of the pretensioning unit 16 by means of an edge region. For the purpose of holding the cutting strand 12, crossed cutting elements of the cutting strand 12 bear against the edge region (FIG. 3). The cutting elements are disposed on the cutter carrier elements 68 of the cutting strand 12 and, in particular, are realized so as to be integral with the cutter carrier elements 68. The cutter carrier elements 68 engage in the holding recess 36 of the pretensioning unit 16 for the purpose of holding the cutting strand 12. In this exemplary embodiment (FIGS. 2 to 4), the resilient pretensioning element 22 is realized as a helical spring. It is also conceivable, however, for the resilient pretensioning element 22 to be realized as another element, considered appropriate by persons skilled in the art, such as, for example, a leg spring, a disk spring, an air spring, a piston, a piezoactive element, etc.

(14) The at least two cutting-strand holding elements 24, 26 together delimit the holding recess 36 of the pretensioning unit 16, at least one distance element 42, 44 of the pretensioning unit 16 being disposed on at least one of the cutting-strand holding elements 24, 26 in order to ensure a feed-through distance 46. The feed-through distance 46 corresponds to a maximum width 38 of the holding recess 36. The feed-through distance 46 extends at least substantially perpendicularly in relation to the cutting plane 58 of the cutting strand 12. The feed-through distance 46 is disposed in mirror symmetry with respect to the cutting plane 58 of the cutting strand 12. In the exemplary embodiment of the power-tool parting device 10 shown here, at least one distance element 42 and a further distance element 44, for ensuring the feed-through distance 46, are respectively disposed on at least one of the cutting-strand holding elements 24, 26. The distance element 42 and the further distance element 44 are disposed, in mirror symmetry in relation to each other with respect to the cutting plane 58 of the cutting strand 12, on one of the at least two cutting-strand holding elements 24, 26. One of the distance elements 42, 44 is disposed on respectively one of the cutting-strand holding elements 24, 26. The distance element 42 and the further distance element 44 are disposed in a circular-ring segment region of the at least two cutting-strand holding elements 24, 26, on the respective cutting-strand holding element of the at least two cutting-strand holding elements 24, 26. It is likewise conceivable that, in an exemplary embodiment of the power-tool parting device 10 that is not represented in greater detail here, the pretensioning unit 16, as an alternative to having the distance element 42 and the further distance element 44, has a single distance element that is disposed on at least one of the cutting-strand holding elements 24, 26 for the purpose of ensuring a feed-through distance 46 and, in particular, has all features of the distance element 42 and of the further distance element 44.

(15) In addition, at least one of the cutting-strand holding elements 24, 26 delimits at least the holding recess 36 of the pretensioning unit 16, which has the maximum width 38 that is less than a maximum cutting strand thickness 40 of the cutting strand 12. The maximum width 38 extends at least substantially perpendicularly in relation to the cutting plane 58 of the cutting strand 12. The maximum cutting strand thickness 40 of the cutting strand 12 corresponds, at least substantially, to a maximum width of the cutter carrier elements 68. Owing to the crossing of the cutting elements, the cutting elements bear against the edge region of at least one of the cutting-strand holding elements 24, 26 that delimits the holding recess 36, in particular side of the edge regions of the cutting-strand holding elements 24, 26 that faces toward the resilient pretensioning element 22 of the pretensioning unit 16.

(16) The pretensioning unit 16 additionally has at least the resilient pretensioning element 22, which is supported via one end 28 on at least one of the cutting-strand holding elements 24, 26 of the pretensioning unit 16, and is supported via another end 30 on at least one of the coupling elements 32, 34 of the guide unit 14 (FIGS. 2 and 3). The cutting-strand holding element 24 has a support face 80, on which the resilient pretensioning element 22 is supported via the end 28. The further cutting-strand holding element 26 has a further support face 82, on which the resilient pretensioning element 22 is supported via the end 28. The resilient pretensioning element 22 bears, via the end 28, against the support faces 80, 82. The support face 80 is disposed on the cutting-strand holding element 24, on a side of an end piece of the cutting-strand holding element 24 that faces toward the guide unit 14. The further support face 82 is preferably disposed on the further cutting-strand holding element 26, on a side of an end piece of the further cutting-strand holding element 26 that faces toward the guide unit 14. The resilient pretensioning element 22 is realized as a spring element, in particular as a helical spring. The pretensioning element 22 bears against the support faces 80, 82 via a coil of the spring element. It is likewise conceivable that, in an exemplary embodiment that is not represented in greater detail here, in which the power-tool parting device 10 has a single cutting-strand holding element, which preferably has a single support face, on which the resilient pretensioning element 22 is supported via one end. While the guide unit 14 is in a state of having been demounted from the coupling device 18 of the portable power tool 20, the translationally movable cutting-strand holding elements 24, 26 can be moved automatically, relative to the coupling elements 32, 34 and the guide unit 14, by a force of the resilient pretensioning element 22, such that the cutting strand 12 is automatically in a tensioned state, and thus automatically effects compensation of play and/or tolerance of the cutting strand 12. Crossed cutting elements of the cutter carrier elements 68 of the cutting strand 12 in this case bear against the edge regions of the cutting-strand holding elements 24, 26 that delimit the holding recess 36, in particular to enable the cutting strand 12 to be held in a mounting position. The cutting strand 12 is brought into a tensioned state as a result of a movement of the cutting-strand holding elements 24, 26 relative to the guide unit 14 and the coupling element 32, and to the further coupling element 34.

(17) The pretensioning unit 16 additionally has at least one force-fit and/or form fit element 48, 50 that is designed to secure at least one of the cutting-strand holding elements 24, 26 of the pretensioning unit 16 against a movement in a cutting plane 58 of the cutting strand 12. Furthermore, the pretensioning unit 16 has at least one force-fit and/or form-fit element 48, 50 that fixes at least two cutting-strand holding elements 24, 26 of the pretensioning unit 16 to each other in a form-fitting and/or force-fitting manner, at least in a cutting plane 58 of the cutting strand 12. Preferably, each of the at least two cutting-strand holding elements 24, 26 has, respectively, at least one force-fit and/or form-fit element 48, 50. The force-fit and/or form-fit element 48 of the cutting-strand holding element 24 is realized such that it corresponds to the force-fit and/or form-fit element 50 of the cutting-strand holding element 26. The force-fit and/or form-fit element 48 of the cutting-strand holding element 24 is preferably realized as a protuberance. The force-fit and/or form-fit element 50 of the cutting-strand holding element 26 is preferably realized as a depression. For the purpose of fixing the at least two cutting-strand holding elements 24, 26 to each other, the force-fit and/or form-fit element 48 of the cutting-strand holding element 24 acts in combination with the correspondingly realized force-fit and/or form-fit element 50 of the cutting-strand holding element 26.

(18) Furthermore, at least one of the cutting-strand holding elements 24, 26 has at least one insertion functional face 52, 54, which is designed to effect at least one force component contrary to a pretensioning force of the pretensioning element 22, at least while the power-tool parting device 10 is being disposed on the coupling device 18. In the exemplary embodiment shown here, both cutting-strand holding elements 24, 26 respectively have at least one insertion functional face 52, 54, which is designed to effect at least one force component contrary to a pretensioning force of the pretensioning element 22, at least while the power-tool parting device 10 is being disposed on the coupling device 18. The insertion functional faces 52, 54 are disposed, at least substantially perpendicular to the cutting plane 58 of the cutting strand 12, on the respective cutting-strand holding elements 24, 26. The insertion functional faces 52, 54 are disposed on the cutting-strand holding elements 24, 26, at an end of the cutting-strand holding elements 24, 26 that faces away from the resilient pretensioning element 22. When the power-tool parting device 10 is being disposed on the coupling device 18 of the portable power tool 20, at least one face of the coupling device 18 of the portable power tool 20, that is realized so as to correspond to the insertion functional faces 52, 54, acts in combination with the insertion functional faces 52, 54. As a result of combined action of the insertion functional faces 52, 54 and the face of the coupling device 18, a force that is directed contrary to a force generated by the pretensioning element 22 can be exerted upon the cutting-strand holding elements 24, 26. The cutting-strand holding elements 24, 26 are moved relative to the guide unit 14. The cutting-strand holding elements 24, 26 can be moved, starting from the drive side 70 of the guide unit 14, in the direction of a side of the guide unit 14 that faces away from the drive side 70, in particular along a direction that is at least substantially parallel to the longitudinal axis of the guide unit 14. The crossed cutting elements are at least substantially without contact to the cutting-strand holding elements 24, 26, in particular to the edge regions of the cutting-strand holding elements 24, 26 that delimit the holding recess 36. A tensioned state of the cutting strand 12, for performing work on a workpiece, is achieved by a tensioning device of the portable power tool 20.